1. Field of the Invention
The present general inventive concept relates to a hard disk drive (HDD), and more particularly, to a suspension assembly and an actuator having the suspension assembly, which has a tip-tab to contact a ramp to park a head.
2. Description of the Related Art
A hard disk drive (HDD), which is one type of information storage device, records data to a disk or reproduces data stored in a disk via a read/write head. The read/write head is moved to a desired position by an actuator while floating at a predetermined height from a recording surface of a rotating disk, so as to read/write data.
A conventional HDD includes a disk, a spindle motor for rotating a disk, a read/write head, and an actuator that moves the read/write head to a desired position on the disk. These components are installed in a base member and protected by a cover member. The actuator includes a swing arm rotatably mounted on an actuator pivot, a suspension assembly which is installed on a front end of the swing arm and which elastically biases a slider having the read/write head toward a surface of the disk, and a voice coil motor (VCM) for rotating the swing arm.
When the HDD is powered and the disk starts rotating, the VCM rotates the swing arm of the actuator counterclockwise so as to move the slider with the read/write head above a recording surface of the disk, and the read/write head reproduces or records data from/on the recording surface of the disk.
When the HDD stops operating, that is, when rotation of the disk is stopped, the VCM rotates the swing arm of the actuator clockwise so as to move the read/write head to a position separated from the recording surface of the disk. By doing so, the VCM prevents the read/write head from hitting the recording surface of the disk. For this, a ramp is installed in the vicinity of the disk, and the suspension assembly includes a tip-tab contacting the ramp.
FIG. 1A is a perspective view of a conventional tip-tab included in a suspension assembly of a HDD. FIG. 1B is a cross-sectional view of portion A1 in the conventional tip-tab of FIG. 1A.
Referring to FIGS. 1A and 1B, the suspension assembly of the HDD includes a tip-tab 20 extending from a front end of a load beam 10. When the HDD stops operating, the tip-tab 20 is placed on a ramp that is installed in the vicinity of a disk, so as to park the read/write head on the ramp. Since the tip-tab 20 is located far away from a pivot center of the actuator, the entire inertia of the suspension assembly is greatly increased even though only a minute weight is added, such that impact properties deteriorate. Thus, in order to reduce the weight of the tip-tab 20, the tip-tab 20 is designed to become gradually narrower in a direction extending away from the load beam 10. Also, in order to enhance the rigidity of the tip-tap 20, the tip-tab 20 is designed to have a convex section toward the ramp.
As the actuator is rotated by a VCM, the tip-tab 20 is in a sliding contact with a surface of the ramp. However, since the width of the tip-tab 20 is narrow at a contact point (portion A1 in FIG. 1A) with the ramp, a curvature radius R1 becomes smaller, such that a contact area between the tip-tab 20 and the ramp becomes smaller. If the contact area between the tip-tab 20 and the ramp is small, the surface of the ramp and a surface of the tip-tab 20 are likely to wear out due to mutual friction, and particles generated by such friction contaminate the inside of the HDD, thereby affecting the operation of the HDD.
FIG. 2A is a perspective view of another conventional tip-tab included in a suspension assembly of a HDD. FIG. 2B is a cross-sectional view of portion A2 in the conventional tip-tab of FIG. 2A.
Referring to FIGS. 2A and 2B, a tip-tab 30 having a constant width may extend from the front end of the load beam 10. In this case, a width of the tip-tab 30 is wide at a contact point (portion A2 in FIG. 2A) with a ramp. In other words, a curvature radius R2 becomes larger, so that a contact area between the tip-tab 30 and the ramp becomes larger, and abrasion between surfaces of the tip-tab 30 and the ramp is reduced. However, when the width of the tip-tab 30 becomes wider, the weight of the tip-tab 30 increases, such that a weight of the suspension assembly is increased, and the impact properties deteriorate.